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## Re: Getting used to Calc's Radian convention

**From**: |
jay . p . belanger |

**Subject**: |
Re: Getting used to Calc's Radian convention |

**Date**: |
Fri, 12 Sep 2014 19:26:08 -0700 (PDT) |

**User-agent**: |
G2/1.0 |

>* > Calc's unit convention of revolution per minute (rpm)*
>* *
>* > is derived from the angular speed and not from a*
>* *
>* > frequency. One does not need to type the factor of `2*
>* *
>* > pi' when calculating, for example, the*
>* *
>* > circumferential velocity from the radius and some*
>* *
>* > value in rpm. So far so good.*
>* *
>* >*
>* *
>* > But it has the slight aesthetic drawback that now the*
>* *
>* > velocity turns out to be in units of radians.*
>* *
>* >*
>* *
>* > n <- 1 rpm*
>* *
>* > r <- 1 m*
>* *
>* > n r -> 2 pi rad m / min*
>* My thoughts are: What?!*
He's referring to Calc (part of Emacs), which can work with units (such as
meters, radians, etc.)
Calc doesn't "know" that the rad probably shouldn't be there; perhaps there
could be a simple way of telling it.